A. It depends on your career goals. Having a higher-status job in a lower-status department isn’t all that bad if you’re happy to stay put. But there’s a risk. One day, your “almost forgotten” unit can get axed in a reorganization. Accepting a lower-status job in a higher-status department makes sense if you think you’d enjoy the new work and you’re willing to prove yourself all over again.
Imagine yourself three years from now. Would you miss your old job or would you be thriving in a hot growth area? Before you get too excited, realize that by taking this transfer you would be operating under a microscope. Management would take far more interest in your work, so you’d be held more accountable, more often. Be prepared not to chafe under such scrutiny. Finally, note the precedent for advancing in your company and industry. Usually, people get ahead faster by producing results in the most visible units than by topping out in the outposts.